1-hydroxylamino-8-sulpho-anthraquinone



Patented June '24, 1930 UNITEDTSTATES PATENT OFFICE ARNOLD SHEPHERDSONAND. ANTHONY JAMES HAILWOOD, OF ENG- LAND, ASSIGNORS TO BRITISHD'YESTUFFS CORPORATION LIMITED, OF MAN- CHESTER, ENGLAND I-HYDROXYLAHINO-8-SULPHOrAKTHBAQUINONE no Drawing. Application filed March as, 1927,Serial are. 179,182, and in Great Britain April 26, 1926.

This invention relates to the reduction of 1-nitroanthraquinone-S-sulphonic acid and its salts and to a new productobtained thereby.

lVe have found that when l-nitroanthraquinone-S-sulphonic acid isreduced in neutral or alkaline solution under less drastic conditionsthan are required for reduction to -1-aminoanthraquinone-8-sulphonicacid, there is obtained a compound having the probable constitution BOaHNHOH oiio cation of one of us (Hailwood, Serial No.

153,47 3, filed December 8,1926), thus providing a new route toindanthrone.

Our invention is illustrated but not lim ited by the following example,in which the parts are by weight.

.Ewample: 20 parts of sodium l-nitroanthraquinone-S-sulphonate arestirred at laboratory temperature with 250 parts of water. A solution of27 parts crystallized sodium sul hide, dissolved in 200 parts water aread ed, and the mixture is agitated until no reaction for sulphide isobtained on testing a sample. The green solution is filtered. The

filtrate, acidified with acetic acid, becomes red and after a timedeposits a greyish urple precipitate of l-hydroxylaminoantraquinone-S-sulphonic acid which may be dried in cold caustic sodasolution. In concentrated sulphuric acid it, becomes yellow and is-converted into an aminohydroxyanthra: quinone sulphonic acid (1 2 2: 8-or 1 4: 8- or a mixture of both), which dissolves in alkaline solutionsgiving a violet color.

Amongst other reducing agents which lead to the same result may bementioned zinc dust and ammonium chloride, glucose and sodium hydroxide,etc.

What we claim and desire to secure by Letters Patent is i As a newmaterial a. substance having the probable structure 5 802B NHOH in whichR stands for H or a metallic atom, which substance, in the form of thefree acid, is a greyish'purple powder, is moderately soluble in water toan orange red solution, dissolves easily with a deep green colour incold caustic soda solution, dissolves in concentratcd sulphuric acid,becoming yellow, and isconverted by boiling aqueous alkali into asulphonated indanthrone.

.In testimony whereof we aflix our signatures. ARNOLD SHEPHERDSON.

ANTHONY JAMES HAILWOOD.

at moderate temperatures without decompos'ition. The compound ismoderately soluble in cold waterto an orange-red solution, and

dissolves easily giving a deep green colour

